Hydrogen lithography breakthrough could make atomic-based storage a reality

Improved technique uses hydrogen gas as an “eraser”, allowing data to be rewritten far more efficiently

Researchers have developed an improved atomic storage manufacturing process that could finally make ultra-efficient, high-density storage solutions a reality.

Ultra-high-density storage devices have been around for a while and typically rely on single molecules or atoms to store bits of information. As the process operates on a far smaller scale than conventional techniques, atomic storage devices can store far more data than today’s hard drives, while consuming anything up to 100 times less power.

While atomic-based fabrication methods are still proof of concept, in theory, they could vastly reduce the environmental impact of IT, at a time where the electricity used to power today’s data centres is under the microscope.

As of yet, previous attempts at forging atomic-based storage devices have encountered several drawbacks that make them practically infeasible, such as a requirement that devices remain in unrealistic environments with extreme temperatures and pressures.

To combat this, last year, researchers from the University of Alberta invented a new fabrication process, called hydrogen lithography, that they claimed could be used to create storage densities of 1.2 petabits per square inch that maintain stability at room temperature. Hydrogen lithography uses the absence or presence of hydrogen atoms to store zeroes and ones on a silicon substrate.

While the technique was a groundbreaking achievement, the researchers’ efforts also ran into some practical drawbacks, namely, that the scanning tunnelling microscope used to rewrite data could not pick up and deposit hydrogen atoms quickly enough, creating a bottleneck.

Now, writing in American Chemical Society, the same researchers claim they have developed a vastly more efficient method of hydrogen lithography that uses “molecular hydrogen repassivation” to develop atomic-scale storage at 1,000-times the speed, potentially making the concept commercially viable for the first time.

The revised technique uses hydrogen gas as an “eraser” to rewrite data instead of a tunnelling microscope. Roshan Achal, Robert Wolkow and colleagues found that by taking away an extra hydrogen atom next to a bit they wanted to rewrite, they could create a reactive bit-site that “attracted” hydrogen gas in the chamber. When bound to the two adjacent sites the hydrogen gas molecule erased them, allowing new binary code to be written.

Given the unlimited supply of hydrogen molecules, the method removes “any restriction” on the number of possible write/rewrite cycles of the memory arrays, the researchers said.

The technique was only demonstrated on a small scale 24-bit memory array, so we are unlikely to see such devices in the data centre anytime soon. Nevertheless, the researchers claimed there were “no physical limitations” preventing the technique from scaling to larger arrays.